Process of making alkali-earth peroxid.



I No Drawing.

rarsnarcn snnerua'or nauov na, GERMAN-Y.

pecification of Letters Patent.

raocnss or MAKING Armani-EART rnaoxrm To all whom it may comm.-

Be it known that I,'-FRIEDRIGH 'BnRGIUs, a citizen of the German Empire,residing at Hanover, Germany, have invented certain new and usefulImprovements in Processes of .Making Alkali-Earth Peroxid of which thefollowing is a specification.

This invention relates to the preparation of the gsuper-oxids of thealkali earths-by processesin which the corresponding oxid is heated in acurrent of air or oxygen. In the preparation of barium peroxi'd for'eX-ample, a somewhat complicated process has".

been hitherto adopted. To obtain a product containing a high percentageof the peroxid the nitrate was raised to the glowing heat at a very hightemperature and the oxid ob tained inthis manner converted into theperoxid at a lower temperature. This method is not a rational onebecause thei nitric acid in combination'withthe'ibarium is completelydecomposed by the high tem} peratureinto nitrogen and oxygen and alsobecause a much higher temperature hasto be used for the preparation ofthe oxid than is necessary for thev subsequent oxidation into theperoxid. The reason for the deviation' thus described lies vinxtheifact'that to obtain a product with .a high percentage "ofperoxidthe oxid .must, be in av very porous condition as otherwise eachparticle of the oxid is given an outer layer of peroxid which v v I g 1.Process for the preparation ofsuperoxids of thealkali earths, consistingin oxidizing the oxide of the alkali earths when dissolved in a. molteninert substance.

protects the inside of the particle from fur ther oxidation.

The-object of this inventioniis to! oven-'- oxid is dissolved in, arelatively" inert substance, such as an alkali for examplein mole tenconditiomand the air or oxy en passed through the molten product, underpressure when necessary-. H v

The invent on also consists 1n separating out from the molten productthe super-oxid inert solvent such as alcohol.

which has been. produced, bypwashingl-the molten product aftercooling-in- The preferred solventsfor the oxidar'e the caustic alkalis,which'have a considerable dissolving action onithe. oxids of the alkaliearths at a'some'what loW. melting point. 1

In carrying out theprocess, the barium oxid for example, isdjssolved inmelted causticsoda and a stream of oxygen is.

passed through I the melted. product'untilthe a relatively barium oxidis completely oxidized into the asappreciably dissociate'slightly abovethe melting point of the solvent, the process isconducted in such mannerthat He conversion into super-oxid takes place in a current of oxygenunder elevated pressure, prefer ably about 100 atmospheres. Aftercooling of themolten massit is-treated with alcohol or a similar solventin order to dissolve the PatentedJan. 23,1912.

Application filed April 11, 1911. Serial No. 620,402.

peroxid. In the manufacture'of suchsuperoxlds, for example, super-oxidof calcium,

caustic soda, the super-oxid which is insoluble being left. The alcoholmay be separated from the-caustic soda by distillat on andboth'substances may be again used'for the process.

The following is a practical example. 100

lbs. of caustic soda are melted in an iron crucibleand raised to atemperature of about .1350" C.

passed through the molten liquid. Fresh i'barium oxidf'is-st-i-rred inas the-barium oxid already in the-molten mass becomes converted'intoinsoluble peroxid. When the oxidation is finished, the deposit isseparated from I I 15 lbs. of barium oxid are thenstirred in' and afterthe oxid has been a thoroughly dissolved, a current of oxygen is I themoltenv mass and washed in alcohol or similar inert solvent for. causticalkali, in

order to 'removeany alkali contained. by the said deposit of super-oxidlWhat Iclaim is:

2. Process for the preparation of super}. i

Ioxids of the alkali earths, consisting in=oxi diz'ing the'ioxids of thealkali earths when dissolved-in an alkali in molten condition. I

Process for. the. preparation. of super-" oxid sfof the alkali earths,consisting in oxithrdu'ghthemolten produc 4.1 Process for thepreparation of superpassing Ila gas, containing free oxygen oxide of thealkali-earths, consisting in oxidizing the. oxids of the alkaliearth's'when dissolved ina molten. inert substance,'and

lot

separating the super-oxid-fby'allowing the molten mass to cool and'then'washing it withlan indifferent solvent agent.

.5. Process for thepreparation. of superoxids'of thealkaliiearths,consistin in oxithe oxids of the alkali cart swhendissolved in a. molten substance, and septreating thernolten productwith a gas conarating the super-03nd by allowlng the moltaming freeoxygen, under elevated pressure. 10

ten mass to cool and then Washing it with In testimony whereof, I afiixmy signature alcohol. i in presence of two Witnesses.

6. Process for the preparation of super-- FRIEDRICH BERGIUS. oxicls ofthe alkali earths, consisting in oxi- VVit-nesses:

dizing the oxids of the alkali earths when ERNEST O. OBERnoL'rznm'dissolved in a molten inert substance by MARTA- L. THOMPSON.

